Speech Enhancement Methods

In general, speech is often corrupted acoustically by ambient noise. The result is the degradation of the performance of digital voice processor, such as speech coder, speech recognition. So a system for speech enhancement is needed strongly to solve the problem. The objective of speech enhancement may be to improve the quality, to increase the intelligibility, to ensure the reliability of digital voice system. Depending on the specific application, the enhancement system may be directed at different objectives.What is contained in the thesis is as following:(1).A variety of methods based on short-time spectrum estimation for speech enhancement are discussed. And an improved method is proposed based on them.(2).In the methods based on a speech model for speech enhancement, the approach based on speech model and kalman filter is discussed.(3).A new method based on masking properties of human ear for speech enhancement is proposed.(4).The proposed methods for speech enhancement are implemented in computer simulation. And the result is satisfactory.